Electrode material and use thereof for the manufacture of an inert anode

Abstract

The invention relates to an electrode material, preferably an inert anode material comprising at least a metal core and a cermet material, characterized in that:said metal core contains at least one nickel (Ni) and iron (Fe) alloy,said cermet material comprises at least as percentages by weight:45 to 80% of a nickel ferrite oxide phase (2) of composition NixFeyMzO4 with 0.60 ≤x≤0.90; 1.90≤y≤2.40; 0.00≤z≤0.20 and M being a metal selected from aluminum (Al), cobalt (Co), chromium (Cr), manganese (Mn), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta) and hafnium (Hf) or being a combination of these metals,15 to 45% of a metallic phase (1) comprising at least one alloy of nickel and copper.

The invention claimed is: 
     
       1. Electrode material comprising at least a metal core and a cermet material, said metal core being at least covered by said cermet material and said cermet material forming an external layer of said electrode material which is designed to be in contact with an electrolysis bath, characterized in that:
 said metal core contains a mixture of nickel (Ni), iron (Fe), and copper (Cu), with proportions by weight of Ni, Fe, and Cu being as follows:
 63%≤Ni≤67%, 
 23%≤Fe≤27%, and 
 8%≤Cu≤12%, and 
 
 said cermet material comprises at least as percentages by weight:
 65 to 69% of a nickel ferrite oxide phase of composition Ni x Fe y M z O 4  with 0.70≤x≤0.85; 2.00≤y≤2.20; 0.00≤z≤0.10 and M being a metal selected from aluminum (Al), cobalt (Co), chromium (Cr), manganese (Mn), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta) and hafnium (Hf) or being a combination of these metals, 
 30 to 34% of a metallic phase comprising at least one alloy of nickel and copper with 85% of Ni and 15% of Cu; and 
 1 to 2% of a monoxide phase of composition Ni x′ Fe 1-x′ O with x′=0.85. 
 
 
     
     
       2. Electrode material according to  claim 1 , characterized in that the proportions by weight of the metal core are: 65% of Ni, 25% of Fe and 10% of Cu. 
     
     
       3. Electrode material according to  claim 1 , characterized in that the metal core of the electrode material further comprises at least one metal A, said metal A being selected from chromium (Cr), manganese (Mn), cobalt (Co) and molybdenum (Mo), with a proportion by weight of metal A in the metal core being as follows: 0.5%≤A≤30%. 
     
     
       4. Electrode material according to  claim 3 , wherein the proportion by weight of metal A in the metal core is 0.5%≤A≤15%. 
     
     
       5. Electrode material according to  claim 1 , characterized in that the metal core further comprises at least one metal M′ selected from aluminum (Al), cobalt (Co), chromium (Cr), manganese (Mn), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta) and hafnium (Hf) or a combination of these metals, with a proportion by weight of metal M′ in the metal core being as follows: 0.5%≤M′≤10%. 
     
     
       6. Electrode material according to  claim 5 , wherein the metal core of the electrode material further comprises at least one metal A, said metal A being selected from chromium (Cr), manganese (Mn), cobalt (Co) and molybdenum (Mo), and the proportions by weight of the metal core are:
 0≤A≤20%; and 
 0.5%≤M′≤5%. 
 
     
     
       7. Electrode material according to  claim 1 , characterized in that the metal core further comprises at least one rare earth element selected from yttrium (Y), cerium (Ce), lanthanum (La) and neodymium (Nd). 
     
     
       8. Electrode material according to  claim 7 , characterized in that the at least one rare earth element counts for up to 5% of a mass of the metal core. 
     
     
       9. Electrode material according to  claim 1 , characterized in that the cermet material further comprises at least one rare earth oxide phase. 
     
     
       10. Electrode material according to  claim 9 , characterized in that the rare earth oxide is selected from Y 2 O 3 , CeO 2 , La 2 O 3  and Nd 2 O 3 . 
     
     
       11. Electrode material according to  claim 9 , characterized in that the rare earth oxide phase is at most 5% of the weight of the cermet material. 
     
     
       12. Electrode material according to  claim 1 , characterized in that the metallic phase of the cermet material further comprises gold (Au) and/or silver (Ag), the percentage by weight of these metals Au and / or Ag not exceeding 5% of the weight of said metallic phase of the cermet material. 
     
     
       13. Electrode material according to  claim 1 , characterized in that a thickness of the cermet material is greater than or equal to 1 mm. 
     
     
       14. Electrode material according to  claim 13 , characterized in that the thickness of the cermet material is between 2 and 8 mm. 
     
     
       15. Electrode material according to  claim 1 , characterized in that the electrode material further comprises at least one intermediate layer arranged between the metal core and the cermet material, said intermediate layer containing at least nickel and being predominantly metallic. 
     
     
       16. Electrode material according to  claim 15 , characterized in that a total thickness of the cermet material and the intermediate layer is greater than or equal to 1mm, said cermet material having a thickness of at least 0.5 mm. 
     
     
       17. Electrode material according to  claim 15 , characterized in that the intermediate layer is a layer of nickel having a thickness of between 200 and 300 microns. 
     
     
       18. Electrode material according to  claim 15 , characterized in that the intermediate layer is a layer of cermet material comprising more than 50% by volume of a metallic phase containing at least nickel. 
     
     
       19. Method of manufacturing an electrode material according to  claim 1 , characterized in that the method comprises:
 preparing the metal core of said electrode material according to a method selected from casting, molding, rolling, hot working, extrusion, or powder metallurgy; and 
 optionally depositing at least one intermediate layer is the metal core; 
 depositing the cermet material on the metal core, or on a last deposited layer of the at least one intermediate layer, said deposition being carried out by a method selected from spraying or powder metallurgy. 
 
     
     
       20. Inert anode made from an electrode material according to  claim 1 . 
     
     
       21. Electrolysis cell comprising at least one inert anode according to  claim 20 . 
     
     
       22. A method comprising producing aluminum by electrolysis in an electrolysis cell according to  claim 21 . 
     
     
       23. Electrode material according to  claim 1 , characterized in that the cermet material is formed on the metal core by sintering. 
     
     
       24. Electrode material according to  claim 23 , characterized in that the metal core is formed by casting prior to sintering the cermet material. 
     
     
       25. Electrode material according to  claim 1 , characterized in that in that the cermet material further comprises 1.5% of Y 2 O 3 .